Lâminas de irrigação e polímero hidroretentor no crescimento e fisiologia de abacaxizeiro cv. Imperial

Pineapple is one of the most cultivated fruit in the world, where Brazil stands out in the international scenario of pineapple production. One of the most important steps in the cultivation of pineapple is the production of seedlings, requiring research on water management at this stage and ways to optimize water consumption, something sought in all agricultural activity in the current scenario, and hydrogel can be a form. to achieve this goal. Given the above, the objective of this study was to evaluate the growth and physiological aspects of pineapple seedlings obtained by stem sectioning submitted to irrigation depths and hydrogel volumes in the substrate. The experiment was conducted in a screened environment in the fruit nursery of the Department of Phytotechnics and Environmental Sciences of the Federal University of Paraíba. The treatments were obtained from the 4x4 factorial arrangement between irrigation depths (10, 40, 70 and 100% of evaporation) and hydrogel volumes (0, 10, 25 and 35 ml), and for the variables plant height, rosette diameter. and number of leaves the arrangement was 4x4x4, because in addition to the factors previously mentioned, there were evaluations at 30, 60, 90 and 120 days after transplantation (DAT). The experimental design was a randomized block design with three replications and two plants per plot. The growth variables evaluated were: plant height, rosette diameter, number of leaves, leaf area, root and shoot dry mass and the relationship between them, except for the first three that were repeated in time. Evaluations were made at 120 DAT. Physiological aspects: chlorophyll a, b and total indices, initial fluorescence, maximum and quantum efficiency of photosystem II, internal carbon dioxide concentration, stomatal conductance, transpiration and liquid carbon dioxide assimilation. The increase of the irrigation depth favored the growth variables, except for root dry mass, because the 66% depth allowed the highest values for this variable. The increase in hydrogel volume favored chlorophyll a, while b and total chlorophylls were not influenced, but had an increase of 40% with the depth. Regarding fluorescence, only the maximum fluorescence was favored by the 70% depth and the other variables were not significant. Both the hydrogel and the depth did not influence the gas exchange of pineapple seedlings.O abacaxizeiro é uma das frutíferas mais cultivadas no mundo, em que o Brasil se apresenta em destaque no cenário internacional de produção de abacaxi. Uma das etapas mais importantes no cultivo de abaxizeiro é a produção de mudas, necessitando de pesquisas quanto ao manejo hídrico nessa fase e formas de otimizar o consumo de água, algo buscado em toda atividade agrícola no cenário atual, e o hidrogel pode ser uma forma de se alcançar esse objetivo. Diante do exposto, objetivou-se no presente trabalho avaliar o crescimento e aspectos fisiológicos em mudas de abacaxizeiro obtidas por seccionamento de caule submetidas a lâminas de irrigação e volumes de hidrogel no substrato. O experimento foi conduzido em ambiente telado no viveiro de Fruticultura do Departamento de Fitotecnia e Ciências Ambientais da Universidade Federal da Paraíba. Os tratamentos foram obtidos do arranjo fatorial 4x4 entre lâminas de irrigação (10, 40, 70 e 100% da evaporação) e volumes de hidrogel (0, 10, 25 e 35 ml), e para as variáveis altura de planta, diâmetro da roseta e número de folhas o arranjo foi 4x4x4, pois além dos fatores anteriormente citados, houve avaliações aos 30, 60, 90 e 120 dias após o transplantio (DAT). O delineamento experimental utilizado foi de blocos casualizados, com três repetições e duas plantas por parcela. As variáveis de crescimento avaliadas foram: altura de planta, diâmetro da roseta, número de folhas, área foliar, massa seca da raiz e parte aérea e a relação entre essas, em que excetuando as três primeiras que foram feitas avaliações repetidas no tempo, as avaliações foram feitas as 120 DAT. Aspectos fisiológicos: índices de clorofila a, b e total, fluorescência inicial, máxima e eficiência quântica do fotossistema II, concentração interna de gás carbônico, condutância estomática, transpiração e assimilação líquida de gás carbônico. O aumento da lâmina de irrigação favoreceu as variáveis de crescimento, exceto para massa seca de raiz, pois a lâmina de 66% foi a que permitiu maiores valores para essa variável. O aumento do volume de hidrogel favoreceu a clorofila a, enquanto as clorofilas b e total não foram influenciadas, mas tiveram aumento com uso da lâmina de 40%. Quanto a fluorescência, apenas a fluorescência máxima foi favorecida pela lâmina de 70% e as demais variáveis não foram significativas. Tanto o hidrogel quanto a lâmina não influenciaram nas trocas gasosas de mudas de abacaxizeiro

Yield performance of okra under potassium fertilization and number of plants per hole

The okra is a vegetable that responds to mineral nutrition and the plant population, with increased production. The work was carried out at the Federal University of Paraíba, in Areia-PB, with the objective of evaluating the influence of K2O doses and number of plants per pit on the yield and quality of okra, cultivating Santa Cruz, in an experimental block design randomized, with treatments distributed in a 6 x 2 factorial scheme, with six K2O doses (0, 50, 100, 150, 200 and 250 kg ha-1), and one and two plants per pit, in four replications. The values ​​for the average mass of fruits, 16 and 18 g were reached as a function of K2O doses, with one and two plants per pit, respectively. The highest numbers of fruits per plant in okra were 45 and 56, at doses of 123.7 and 184 kg ha-1 of K2O, respectively for one and two plants per pit, and the highest fruit production per plant was 584.2 g, with two plants per pit and 250 kg ha-1 of K2O. The total fruit yield was 42.13 t ha-1, in the treatment with two plants per pit and 100 kg ha-1 of K2O, and the doses of 122.5 and 115 kg ha-1 of K2O were responsible for the higher productivity of commercial fruits in okra, 25.6 and 29.2 t ha-1, respectively, with one and two plants per pit, and the leaf K content was influenced only by K2O doses. Keywords: Abelmoschus esculentus; mineral fertilizers; plant densit

Rendimento de abobrinha em resposta à adubação com diferentes doses e fontes de potássio

Potassium (K) is essential nutrient to the physiological and biochemical activities of plants, acting in the cation-anion balance, water movement, osmoregulation, and transference of energy. This study aimed to evaluate the yield response of the zucchini squash cultivar 'Caserta' to different doses and sources of potassium. The experiment was carried out under field conditions in a complete randomized block experimental design in a 6 x 2 factorial scheme, with six K2O doses (0, 50, 100, 150, 200, and 250 kg ha-1) and two sources (chloride and potassium sulfate), with four replications. The fruit mass, fruit length, number of fruits per plant, total and marketable fruit yields were evaluated. The results showed that the sulfate and potassium chloride sources promoted the maximum length and number of fruits per plant. K2O fertilization in the form of potassium sulfate promoted higher mass and total fruit yield. The doses of 108.41 and 130.78 kg ha-1 of K2O in the chloride and potassium sulfate sources provided the maximum marketable yield of fruits, with 22.84 and 27.0 t ha-1, respectively. Regardless of the source, potassium fertilization must be provided to increase the production parameters of the zucchini squash 'Caserta' cultivar